1. Field of the Invention
The present invention relates to a collapsible container, and more particularly to a collapsible, blow molded plastic container that includes a pair of opposed, V-shaped side panels in which the apex of the V extends inwardly to define a longitudinally extending hinge or fold line along each side panel.
2. Description of the Related Art
The rapidly increasing use of blow molded plastics containers has caused significant disposal problems when the bottles are disposed of after use. In addition to the nonbiodegradability of the plastics materials from which such containers are most commonly made, the containers typically retain their original shape and are not crushed by users, thereby occupying substantial space in waste disposal sites, such as municipal landfills. Part of the reason for the absence of any significant effort on the part of users to crush or compress such containers derives from the fact that it is often difficult to do so, because of the rigidity of the containers.
Over the years several proposals have been put forward relative to the provision of a collapsible container. For example, in U.S. Pat. No. 3,367,380, which issued Feb. 6, 1968, to J. W. Dickey, there is shown a collapsible plastic container suitable for liquids and viscous materials, in which side and end walls include fold lines to permit the container to be collapsed by pressing together the rear and face panels of the container. The provision of corrugations or ribs on the front and rear panels is disclosed for providing additional strength.
Another form of collapsible container is disclosed in U.S. Pat. No. 3,727,803, which issued Apr. 17, 1973, to James Campbell Cobb. That patent discloses a molded, low density polyethylene container having a base and two opposed sides that are formed with a V-shaped fold or indentation that extends vertically so that the container can be collapsed in the same manner that a bellows is closed.
Although containers having V-shaped side walls have been disclosed for permitting the containers to be collapsed after use, the disclosed structures include shortcomings that derive from the configurations of the containers. For example, when such containers are filled with a liquid, unless the side walls are sufficiently thick to withstand the outward pressure exerted on the container walls to cause them to bow outwardly, the force necessary to collapse the container becomes excessive and discourages users from even attempting to collapse the bottles after the product has been consumed. On the other hand, if the walls of the container are sufficiently thin to permit collapse of the containers without undue force, the walls of the container tend to bulge outwardly, particularly in warmer weather when the bottle materials become more flexible with increasing temperature.
It is an object of the present invention to provide a collapsible bottle in which the walls of the bottle are sufficiently thin to facilitate collapsing, and that also is so configured as to minimize outward bulging of the walls of the container when it is filled with a liquid material.